According to certain embodiments, a method by a radio node (110, 115) operating in multiple modes for power detection includes operating in a first mode. While operating in the first mode power levels of transmissions on a channel are compared to a first threshold to determine whether the channel is free. While operating the radio node (110, 115) in the first mode, power levels within a specified range are detected during a first time period. In response to detecting the power levels within the specified range during the first time period, the radio node (110, 115) is switched to a second mode that is a duty-cycle mode. While operating the radio node (110, 115) in the second mode, the power levels of the transmissions on the channel are compared to a second threshold during a first portion of a duty cycle and to a third threshold during a second portion of the duty cycle to determine whether the channel is free. The third threshold is different from the second threshold. In response to determining that the channel is free, transmission is initiated on the channel.